I. Field of the Invention
The present invention relates to apparatus for providing a visual display responsive to an audio signal.
Such devices add visual reenforcement to an audio performance. It is an object of the present invention to provide such a display apparatus which is suitable for use in percussion sections of marching bands, thereby visually enhancing the appearance and appreciation of these percussion sections. The present invention is particularly useful in connection with drums in a percussion section whose intricate patterns are often lost in the totality of the band's complete arrangement. Furthermore, since many marching bands of today compete against each other, there is a need to be able to elicit a noticeably increased response from the viewing audience and impress the judges so as to increase the band's chances for obtaining the top score in competition.
The present invention, therefore, has as an object the ability to visually display the various combination of patterns, beats, and rhythms being played by the percussion section, thereby adding visual reenforcement to what the audience and judges are hearing.
II. Description of the Prior Art
To fulfill this identified need, a display device requires the ability to instantaneously respond to very rapid changes in the amplitude of audio signals generated by a percussion section of a band. Prior art display devices, such as that disclosed in U.S. Pat. No. 3,719,857 issued to Sharp, recognized that incandescent lamps have an inherent slow response time and, hence, appear unable to achieve the very rapid light intensity modulation required for such visual displays. As explained in Sharp, the slow response of incandescent lamps causes their brightness to remain more or less constant while important short term musical effects are occurring. The resultant optical display of such prior art devices is, therefore, of limited interest.
Accordingly, Sharp turns to the use of fluorescent, ultraviolet or other gas discharge devices to facilitate very rapid intensity modulation in response to an audio signal.
However, gas discharge lamps require large power sources and are, accordingly, unsuited for portable operation. In fact, even incandescent display devices suffer from relatively high current drain requirements, thereby severely limiting how long such devices can operate without replacing or recharging the required portable power supply. U.S. Pat. No. 3,798,638 issued to Goldschmied attempts to minimize such high current drain by driving an incandescent lamp through a current limiting transistor at nominal rating until maximum illumination intensity of the incandescent lamps is reached. This approach, however, risks burn-out of the lamps in the event that intensity is not timely reduced, requires a sophisticated control to assure reduction of intensity, and, subjects the lamps to an extremely high initial current draw or inrush current upon application of the voltage. Furthermore, the current limiting transistor is power consuming and prevents maximum utilization of available voltage.
It is, accordingly, an object of the present invention to provide a display apparatus which exhibits a visually attractive light reenforcement to accompany sound output of a percussion instrument such as a drum.
Another object of the present invention is to provide such a display apparatus wherein the relative intensity of the light output is proportional to the relative intensity of the sound output, with the periodicity of the light output being in step with the periodicity of the sound output.
A further object of the present invention is to provide such a visual display which has a minimum power requirement and, accordingly, may be portably operated. Preferably, the display may be portably operated for at least 15 minutes of normal playing time.
It is also an object of the present invention to provide such a display system which is ruggedly constructed, so as to withstand relatively severe shock, vibrations, and general abuse, which is normal and common to occur to the types of instruments into which this system is intended to be installed.
A still further object of the present invention is to provide such a display system so designed and constructed as to facilitate its installation into both new instruments at the factory level and into old instruments already in the field, by personnel having a minimum of mechanical aptitude and utilizing generally available tools.
Furthermore, it is still another object of the present invention to provide such a display system which is reasonably priced.
Additional objects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out in the appended claims.